This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal is to use models and algorithms developed by the Virtual Photonics core to extend the application of DOSI to wavelength regions and path lengths for which standard diffusion models are known to fail. We will investigate analytic models (such as the delta-p1) as well as monte carlo methods (such as pMC) for this task.